Switchgear assemblies, switchboards and panelboards are general terms which cover metal enclosures, housing switching and interrupting devices such as fuses, and circuit breakers, along with associated control, instrumentation and metering devices. Such assemblies typically include associated bus bars, interconnections and supporting structures used for the distribution of electrical power. Low voltage switchgear and switchboards operate at voltages up to 600 volts and with continuous currents up to 5000 amps or higher. Such devices are also designed to withstand short circuit currents ranging up to 200,000 amps (3 phase RMS symmetrical).
Typical switchgear equipment is composed of a lineup of several metal enclosed sections. Each section may have several circuit breakers stacked one above the other vertically in the front of the section with each breaker being enclosed in its own metal compartment. Each section has a vertical or section bus which supplies current to the breakers within the section via short horizontal branch buses. The vertical bus bars in each section are supplied with current by a horizontal main bus bar that runs through the lineup of metal enclosed sections. A typical arrangement includes bus bars for each electrical phase of a multiple phase system which may include three power phases and a neutral.
The bus bars typically are joined by bus bar joints in the switchgear line-up. Bus bar joints typically are assembled with bolts that must be accessible for routine maintenance, for example, tightening or replacing bus bars. Bus bar assemblies typically increase in thickness as the current rating of the switchgear equipment increases. It is also typical to provide insulation of various components within a switchgear enclosure including a cover of the bus bar joints.
Installation of bus bars are rather labor intensive and require careful assembly. A problem faced during installation is aligning and supporting the horizontal bus bars to the vertical bus bars in an efficient and expeditious manner. The present invention facilitates the installation process by provisioning a means of aligning and supporting adjacent horizontal bus bars as they are being installed on the vertical bus bars.
Thus, there is a need for a bus joint assembly for use in switchgear equipment that will align and support bus bars. There is a further need for a bus joint assembly that may be used with various bus bar configurations. There is an additional need for a bus joint assembly that can facilitate the installation process.